It's all a personal choice and I can understand those who prefer iOS. Overall, it is the more refined user experience.
However, there's a ton holding me firmly on the Android side: Notification light, back button, superior camera hardware (even now with the new iPhone 7), expandable storage, fast charging, wireless charging, audio jack, larger screen to body ratio (this is big).
There are couple of apps and they alone are worth staying with Android - Tasker and Nova Launcher. If you don't use them, the gap between Android and iOS is not THAT great and I can see +/- for both. If you do though, they make iOS look like a 1980s calculator compared to a modern time top of the line laptop. They alone define the term "smart phone". You can train you phone to do stuff for you (Tasker) so you can live your life and interact less with it. Nova let's you design your entire interface. Between, Nova, Themes and Textra, my phone interface is customized exactly to my taste with all dark theme.
There are things to iOS that I find frustrating:
- alarm sound volume is linked to the system notification volume so you have to turn your phone sound down every night. Find this ultra dumb. On Android it is all separated as it should be.
- When you get a call you don't want to take (on lock screen only), on iOS you have only one option and that is to answer it. You don't get an equivalent swipe reject option (that just bogles my mind, why?)
- Setting default apps! - this is another big one and I can't believe iOS to this day excludes it intentionally. Things like my navigation and keyboard apps, not integrated properly unless you want to use the Apple equivalent. For the price I pay for this device, I'd like to be able to make my own choice what/how I use. Same way I would on a laptop.
There's more to it. Like I said, not everyone is as geeky as I, and some people just need a basic phone that just works. IOS give you exactly that. Android, although not perfect (diluted OS by wireless carriers) gives you some extremely robust options if you're willing to learn. They make your phone, in certain ways, more powerful than a laptop.